Bolt Hold Open Facility

ABSTRACT

A bolt hold open facility is provided for a firearm with a bolt reciprocating along a bolt path. The bolt hold open facility comprises a latch having a bolt contact portion, the latch being movable between an extended position and a retracted position, the bolt contact portion adapted to extend into the bolt path to restrain the bolt when the latch is in the extended position, the bolt contact portion adapted to be positioned clear of the bolt path to enable movement of the bolt when the latch is in the retracted position. The latch is biased to the extended position. The bolt hold open facility comprises an actuator operably engaged to the latch and adapted to move the latch to the retracted position.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No.: 62/470,485, filed Mar. 13, 2017, which is hereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to bolt manipulation facilities for firearms.

BACKGROUND OF THE INVENTION

Many semi-automatic, autoloading, and self-loading firearms are configured to fire a single round each time the trigger is pressed. These semi-automatic, autoloading, and self-loading firearms perform all steps necessary to prepare the next round after each round is fired. These steps include extracting and ejecting a spent cartridge case from a firing chamber, re-cocking a firing mechanism, stripping a new cartridge from a magazine, and loading the new cartridge into the firing chamber. Many semi-automatic, autoloading, and self-loading firearms, including rifles based on the Armalite Rifle (AR) platform (e.g. AR-15, M16, M4, and AR-10), comprise bolt catch devices. A traditional bolt catch device is biased lightly downward to stay clear of a bolt reciprocation path until the stronger upward force of a magazine follower biases the traditional bolt catch into the bolt reciprocation path when the magazine is empty.

Laws in many states may restrict the ownership and/or use of many semi-automatic, autoloading, and self-loading firearms such as rifles based on the AR platform. Laws in many states may restrict specific types of accessories for many semi-automatic, autoloading, and self-loading firearms such as rifles based on the AR platform.

Bolt hold open facilities and elements are needed to prevent otherwise semi-automatic, autoloading, and self-loading firearms from automatically stripping a new cartridge from a magazine, and loading the new cartridge into a firing chamber.

SUMMARY OF THE INVENTION

At least some embodiments of the present invention provide a bolt hold open facility for a firearm with a bolt reciprocating along a bolt path. The facility comprises a latch having a bolt contact portion. The latch is movable between an extended position and a retracted position. The bolt contact portion is adapted to extend into the bolt path to restrain the bolt when the latch is in the extended position. The bolt contact portion is adapted to be positioned clear of the bolt path to enable movement of the bolt when the latch is in the retracted position. The latch is biased to the extended position. The facility comprises an actuator operably engaged to the latch and adapted to move the latch to the retracted position.

According to some of the various embodiments, a firearm may define a primary axis and a bolt hold open receptacle slot perpendicular to the primary axis. The firearm may include a pivot pin parallel to the primary axis. A latch may define a pivot aperture closely receiving the pivot pin.

According to some of the various embodiments, a latch including an actuator may be a single integral element. The latch may include a planar plate portion. The planar plate portion may define a bore. The bore may be configured to receive a coil spring. The planar plate portion may have a lower periphery. The bore may have an opening at the lower periphery.

At least some embodiments of the present invention provide a firearm comprising a frame defining a bolt passage. The firearm comprises a bolt adapted to reciprocate within the bolt passage between a retracted position and a battery position. The firearm comprises a magazine well adapted to retain a magazine proximate the bolt passage. The bolt is adapted to strip a round from the magazine and chamber the round in the barrel when transitioning from the retracted position to the battery position. The firearm comprises a latch having a bolt contact portion. The latch is movable between an extended position and a retracted position. The bolt contact portion is adapted to extend into the bolt path to restrain the bolt when the latch is in the extended position. The bolt contact portion is adapted to be positioned clear of the bolt path to enable movement of the bolt when the latch is in the retracted position. The latch is biased to the extended position. An actuator is operably engaged to the latch and adapted to move the latch to the retracted position.

According to some of the various embodiments, a latch may be proximate the magazine well. The latch position may be based entirely on the actuator, irrespective of the presence of condition of a magazine in the magazine well.

According to some of the various embodiments, a frame may define a primary axis. The frame may define a bolt hold open receptacle slot perpendicular to the primary axis. The frame may include a pivot pin parallel to the primary axis. A latch may define a pivot aperture closely receiving the pivot pin.

According to some of the various embodiments, a firearm may include a spring applying a vertical upward force to a latch.

At least some embodiments of the present invention provide a bolt hold open element having a planar plate portion defining a bore configured to receive a coil spring. The bolt hold open element has a bolt contact portion. The coil spring is configured to bias the bolt contact portion in an upward bias when employed in a firearm.

According to some of the various embodiments, a bolt hold open element may have an actuator adapted to move the element to a retracted position when employed in a firearm. The bolt hold open element may have a pivot aperture configured to closely receive a pivot pin when the pivot pin is employed to secure the element to the firearm.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example bolt hold open facility installed in an example firearm according to various aspects of various embodiments.

FIG. 2 illustrates an example bolt hold open facility installed in a lower receiver of an example firearm in accordance with various aspects of various embodiments.

FIGS. 3A and 3B illustrate an aspect of an example bolt hold open facility in accordance with an embodiment.

FIG. 4 illustrates an example bolt hold open facility in a retracted position in accordance with various aspects of various embodiments.

FIG. 5 illustrates an example bolt hold open facility in an extended position in accordance with various aspects of various embodiments.

FIG. 6 illustrates an exploded view of an example bolt hold open facility and a lower receiver of an example firearm in accordance with various aspects of various embodiments.

FIG. 7 illustrates an exploded view of an example bolt hold open facility and a lower receiver of an example firearm in accordance with various aspects of various embodiments.

FIG. 8 illustrates an exploded view of an example bolt hold open facility and a lower receiver of an example firearm in accordance with various aspects of various embodiments.

DESCRIPTION OF THE CURRENT EMBODIMENT

Embodiments of the invention now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention. Like numbers refer to like elements throughout.

Certain embodiments of the invention provide a bolt hold open facility.

FIG. 1 illustrates an example bolt hold open facility installed in an example firearm according to various aspects of various embodiments. The firearm may comprise a bolt 20 configured to reciprocate along a bolt path. The bolt hold open facility may comprise a latch 10. The latch 10 may be movable between an extended position and a retracted position. The latch 10 may be biased to the extended position, as shown. The firearm may include a spring that applies a vertical upward force to the latch 10. When in the extended position, the latch 10 may be adapted to extend into the bolt path to restrain the bolt 20. When the bolt 20 is restrained, a round of ammunition 22 may not be automatically stripped from a magazine 26 and chambered in a barrel 29. The firearm may comprise a magazine well. The magazine 26 may be retained in the magazine well. The latch 10 may be proximate the magazine well. The bolt hold open facility may comprise an actuator. The actuator may comprise an actuator surface 14. The actuator may be operably engaged to the latch 10 and adapted to move the latch to the retracted position. The latch 10 including the actuator may be a single integral element. The latch 10 position may be based entirely on the actuator, irrespective of the presence of condition of a magazine 26 in the magazine well.

According to various embodiments, a firearm may comprise a frame. The frame may comprise a lower receiver 24 and an upper receiver 28. The upper receiver 28 may define a bolt passage. The firearm may comprise a bolt 20. The bolt 20 may be adapted to reciprocate within the bolt passage between a retracted position and a battery position. The firearm may comprise a magazine well adapted to retain a magazine 26 proximate the bolt passage. The bolt 20 may be adapted to strip from the magazine 26 and chamber a round 22 in a barrel 29 when transitioning from the retracted position to the battery position.

According to various embodiments, a bolt hold open facility may require manual actuation by a user of a firearm to chamber each successive round after firing. The manual actuation may require pressure on actuator surface 14. The pressure on actuator surface 14 may need to be great enough to overcome the pressure applied by a spring that applies a vertical upward force to a latch 10.

FIG. 2 illustrates an example bolt hold open facility installed in a lower receiver 24 of an example firearm in accordance with various aspects of various embodiments. The bolt hold open facility may comprise a latch 10. The latch 10 may be movable between an extended position and a retracted position. The latch 10 may be biased to the extended position, as shown. When in the extended position, the latch 10 may be adapted to extend into a bolt path to restrain a bolt 20. When the bolt 20 is restrained, a round of ammunition 22 may not be automatically stripped from a magazine 26 and chambered in a barrel (not shown). The firearm may comprise a magazine well. The magazine 26 may be retained in the magazine well. The bolt hold open facility may comprise an actuator. The actuator may comprise an actuator surface 14. The actuator may be operably engaged to the latch 10 and adapted to move the latch to the retracted position. The firearm may comprise a latch pivot pin bore 32 configured to secure the latch 10 in the firearm through employment of a pivot pin.

FIGS. 3A and 3B illustrate an aspect of an example bolt hold open facility in accordance with an embodiment. The bolt hold open facility may comprise a latch and a coil spring 11. The latch may comprise a bolt contact portion 12. The bolt contact portion 12 may be adapted to extend into a bolt path of a firearm to restrain a bolt when the latch is in an extended position. The bolt contact portion 12 may be adapted to be positioned clear of the bolt path to enable movement of the bolt when the latch is in the retracted position. The latch may include a planar plate portion 18. The planar plate portion 18 may define a bore 19. The planar plate portion 18 may have a lower periphery 17. The bore 19 may have an opening at the lower periphery 17. The bore 19 may be adapted to receive the coil spring 11. The latch may define a pivot aperture 16. The pivot aperture 16 may be adapted to closely receive a pivot pin. The latch may comprise an actuator. The actuator may comprise an actuator surface 14. The latch may optionally comprise an engagement actuator. The engagement actuator may comprise an engagement surface 15. In a traditional mil-spec bolt catch, an engagement actuator is needed to engage the bolt catch to extend into the bolt path. However, with a the bolt hold open facility biased to the extended position, the engagement actuator may not be needed during normal operation. The engagement actuator may be adapted to move the latch to the extended position if coil spring 11 is not installed, not installed properly, or fails during use. A bolt hold open facility may fit in a mil-spec frame or lower receiver without any further modification to the mil-spec frame or receiver. The actuator surface 14 and/or the engagement surface 15 may be extended. For example, actuator surface 14 and/or the engagement surface 15 may be extended to be operable by a trigger finger.

According to various embodiments, a bolt hold open facility may be a modified version of a traditional mil-spec bolt catch. The modified version may comprise bore 19 and coil spring 11. Alternatively, the modified version may comprise a coil spring 11 bonded to a lower periphery 17 of a traditional mil-spec bolt catch without bore 19. However, persons of ordinary skill in the art will recognize alternative methods to a coil spring in order to bias a latch and/or a bolt contact portion 12 in an extended position. For example, a leaf spring, lifting actuator, solenoid, and/or magnet may be employed to bias the latch and/or the bolt contact portion 12 in an extended position. The latch may be composed of ferrous, nonferrous, and/or polymer materials.

FIG. 4 illustrates an example bolt hold open facility in a retracted position in accordance with various aspects of various embodiments. The bolt hold open facility may be installed in a firearm (e.g. lower receiver 24). The bolt hold open facility may comprise a latch 10 and a coil spring 11. The latch 10 may be biased to an extended position. Pressure may need to be applied to latch 10 (for example by a finger of a user, as shown) to move the latch to a retracted position, as shown. In the retracted position, a bolt 20 of a firearm may be free to move from a retracted position, as shown, to a battery position.

FIG. 5 illustrates an example bolt hold open facility in an extended position in accordance with various aspects of various embodiments. The bolt hold open facility may be installed in a firearm (e.g. lower receiver 24). The bolt hold open facility may comprise a latch 10 and a coil spring 11. The latch 10 may be biased to an extended position, as shown. In the extended position, the latch 10 may be adapted to extend into a bolt path to restrain a bolt 20 in a retracted position, as shown.

FIG. 6 illustrates an exploded view of an example bolt hold open facility and a lower receiver 24 of an example firearm in accordance with various aspects of various embodiments. The bolt hold open facility may comprise a latch and a coil spring 11. The latch may comprise a bolt contact portion 12. The latch may include a planar plate portion 18. The planar plate portion 18 may define a bore 19. The bore 19 may be adapted to receive the coil spring 11. The latch may define a pivot aperture 16. The pivot aperture 16 may be adapted to closely receive a pivot pin 35. The pivot pin 35 may comprise a roll pin or a machine screw. The latch may comprise an actuator. The actuator may comprise an actuator surface 14. The latch may optionally comprise an engagement surface 15. The firearm may define a primary axis. The firearm may define a bolt hold open receptacle slot 30 perpendicular to the primary axis. The firearm may comprise a latch pivot pin bore 32. The latch pivot pin bore 32 may be adapted to receive a pivot pin 35 parallel to the primary axis. In a traditional mil-spec bolt catch, a mil-spec bolt catch plunger 42 is lightly pressured by a mil-spec bolt catch spring 41 to bias the traditional mil-spec bolt catch in a retracted position. A mil-spec bolt catch spring bore 40 may be adapted to receive the mil-spec bolt catch plunger 42 and the mil-spec bolt catch spring 41. However, for installation of the bolt hold facility, the mil-spec bolt catch plunger 42 and mil-spec bolt catch spring 41 may be omitted.

According to various embodiments, a firearm may comprise a frame. The frame may comprise a lower receiver 24. The frame may define a primary axis. The frame may define a bolt hold open receptacle slot 30 perpendicular to the axis. The frame may include a pivot pin 35 parallel to the primary axis. A latch 10 may define a pivot aperture 16. The pivot aperture 16 may be adapted to closely receive the pivot pin 35.

According to various embodiments, a bolt hold open element may comprise a planar plate portion 18. The planar plate portion 18 may define a bore 19. The bore 19 may be configured to receive a coil spring 11. The coil spring 11 may be press fitted in the bore 19. The coil spring 11 may be press fitted via an outside diameter of the coil spring 11. The bore 19 may comprise a boss adapted to receive an inside diameter of the coil spring 11. The coil spring 11 may be press fitted via the inside diameter. The coil spring 11 may be bonded, welded, and or fastened to the planar plate portion 18. The bolt hold open element may comprise a bolt contact portion 12. The coil spring 11 may be configured to bias the bolt contact portion 12 in an upward bias when employed in a firearm. The bolt hold open element may comprise an actuator adapted to move the element to a retracted position when employed in the firearm. The bolt hold open element may comprise a pivot aperture 16 configured to closely receive a pivot pin 35 when the pivot pin 35 is employed to secure the element to the firearm.

FIG. 7 illustrates an exploded view of an example bolt hold open facility and a lower receiver 24 of an example firearm in accordance with various aspects of various embodiments. The bolt hold open facility may comprise a latch and a coil spring 11. The latch may include a planar plate portion 18. The planar plate portion 18 may define a bore 19. The bore 19 may be adapted to receive the coil spring 11. The latch may define a pivot aperture 16. The pivot aperture 16 may be adapted to closely receive a pivot pin 35. The pivot pin 35 may comprise a roll pin or a machine screw. The latch may comprise an actuator. The actuator may comprise an actuator surface 14. The latch may optionally comprise an engagement surface 15. The firearm may define a primary axis. The firearm may define a bolt hold open receptacle slot 30 perpendicular to the primary axis. The firearm may comprise a latch pivot pin bore 32. The latch pivot pin bore 32 may be adapted to receive a pivot pin 35 parallel to the primary axis. In a traditional mil-spec bolt catch, a mil-spec bolt catch plunger 42 is lightly pressured by a mil-spec bolt catch spring 41 to bias the traditional mil-spec bolt catch in a retracted position. A mil-spec bolt catch spring bore 40 may be adapted to receive the mil-spec bolt catch plunger 42 and the mil-spec bolt catch spring 41. However, for installation of the bolt hold facility, the mil-spec bolt catch plunger 42 and mil-spec bolt catch spring 41 may be omitted.

FIG. 8 illustrates an exploded view of an example bolt hold open facility and a lower receiver 24 of an example firearm in accordance with various aspects of various embodiments. The bolt hold open facility may comprise a latch and a coil spring 11. The latch may include a planar plate portion 18. The planar plate portion 18 may define a bore. The bore may be adapted to receive the coil spring 11. The latch may define a pivot aperture. The pivot aperture may be adapted to closely receive a pivot pin 35. The pivot pin 35 may comprise a roll pin or a machine screw. The latch may comprise an actuator. The actuator may comprise an actuator surface 14. The latch may optionally comprise an engagement surface 15. The firearm may define a primary axis. The firearm may define a bolt hold open receptacle slot 30 perpendicular to the primary axis. The firearm may comprise a latch pivot pin bore (32A and 32B). The latch pivot pin bore (32A and 32B) may be adapted to receive a pivot pin 35 parallel to the primary axis. A mil-spec bolt catch spring bore 40 may be adapted to receive a mil-spec bolt catch plunger and a mil-spec bolt catch spring. However, for installation of the bolt hold facility, the mil-spec bolt catch plunger and mil-spec bolt catch spring may be omitted.

A person of ordinary skill in the art will appreciate that components shown in and described with respect to the figures are provided by way of example only. Numerous other configurations are possible. Accordingly, embodiments of the invention should not be construed as being limited to any particular configuration. It will be appreciated that while the disclosure may in certain instances describe a single example embodiment, there may be other configurations, shapes, and orientations of facilities and components without departing from example embodiments of the invention. A person of ordinary skill in the art will recognize the applicability of embodiments of the invention to various firearms, firearm components, rail assemblies, sighting systems, and combinations thereof known in the art. A person of ordinary skill in the art may recognize that embodiments of the invention may comprise forged, milled, and/or printed parts comprising one material or a plurality of materials. A person of ordinary skill in the art will appreciate that components and elements shown in and described with respect to FIGS. 1-8 are provided by way of example only. Numerous other bolt manipulation facilities, firearms, firearm components, and various component configurations are possible. Accordingly, embodiments of the invention should not be construed as being limited to any particular bolt, firearm, or firearm component. Additionally, it is to be recognized that, while the invention has been described above in terms of one or more embodiments, it is not limited thereto. Various features, aspects, and/or components of the above described invention may be used individually or jointly. Accordingly, the claims set forth below should be construed in view of the full breadth of the embodiments as disclosed herein. 

I claim:
 1. A bolt hold open facility for a firearm with a bolt reciprocating along a bolt path, the facility comprising: a latch having a bolt contact portion; the latch being movable between an extended position and a retracted position; the bolt contact portion adapted to extend into the bolt path to restrain the bolt when the latch is in the extended position; the bolt contact portion adapted to be positioned clear of the bolt path to enable movement of the bolt when the latch is in the retracted position; the latch being biased to the extended position; and an actuator operably engaged to the latch and adapted to move the latch to the retracted position.
 2. The facility according to claim 1, wherein the firearm defines a primary axis and defines a bolt hold open receptacle slot perpendicular to the primary axis, and including a pivot pin parallel to the primary axis and the latch defining a pivot aperture closely receiving the pivot pin.
 3. The facility according to claim 1, wherein the latch including the actuator is a single integral element.
 4. The facility according to claim 1, wherein the latch includes a planar plate portion defining a bore receiving a coil spring.
 5. The facility according to claim 4, wherein the planar plate portion has a lower periphery and the bore has an opening at the lower periphery.
 6. A firearm comprising: a frame defining a bolt passage; a bolt adapted to reciprocate within the bolt passage between a retracted position and a battery position; a magazine well adapted to retain a magazine proximate the bolt passage; the bolt adapted to strip from the magazine and chamber a round in the barrel when transitioning from the retracted position to the battery position; a latch having a bolt contact portion; the latch being movable between an extended position and a retracted position; the bolt contact portion adapted to extend into the bolt path to restrain the bolt when the latch is in the extended position; the bolt contact portion adapted to be positioned clear of the bolt path to enable movement of the bolt when the latch is in the retracted position; the latch being biased to the extended position; and an actuator operably engaged to the latch and adapted to move the latch to the retracted position.
 7. The firearm according to claim 6, wherein the latch is proximate the magazine well.
 8. The firearm according to claim 6, wherein the latch position is based entirely on the actuator, irrespective of the presence of condition of a magazine in the magazine well.
 9. The firearm according to claim 6, wherein the frame defines a primary axis and defines a bolt hold open receptacle slot perpendicular to the primary axis, and including a pivot pin parallel to the primary axis and the latch defining a pivot aperture closely receiving the pivot pin.
 10. The firearm according to claim 6, wherein the latch including the actuator is a single integral element.
 11. The firearm according to claim 6, wherein the latch includes a planar plate portion defining a bore receiving a coil spring.
 12. The firearm according to claim 11, wherein the planar plate portion has a lower periphery and the bore has an opening at the lower periphery.
 13. The firearm according to claim 6, including a spring applying a vertical upward force to the latch.
 14. A bolt hold open element having: a planar plate portion defining a bore configured to receive a coil spring; and a bolt contact portion; wherein the coil spring is configured to bias the bolt contact portion in an upward bias when employed in a firearm.
 15. The element according to claim 14, further having an actuator adapted to move the element to a retracted position when employed in the firearm.
 16. The element according to claim 14, further having a pivot aperture configured to closely receive a pivot pin when the pivot pin is employed to secure the element to the firearm. 